1. Field of the Invention
The present invention relates generally to a device for servicing a cooling system of the type utilizing a compressible refrigerant as the cooling medium and, specifically, to a device for drawing off and subsequently charging refrigerant in a cooling system.
2. Description of the Prior Art
Cooling systems, such as automotive air conditioning systems, periodically require servicing to insure optimum operating conditions. Additionally, maintenance on such systems generally requires shutting down the system and drawing off the coolant in order to dismantle the component parts of the system. Normally, when such cooling systems break down or require maintenance, the refrigerant is vented to the atmosphere and lost or wasted. This is because the cooling unit cannot be serviced with the refrigerant intact. Obviously, this results in a costly waste of valuable material.
It has also been determined in recent years that fluorocarbons, such as the type commonly used in cooling systems, are harmful to the environment and it is now considered desirable to prevent the uncontrolled release of refrigerants to the atmosphere. It is also a cost savings to be able to recover used refrigerants for reuse in the air conditioning system.
While various recovery and reprocessing systems are known for recovering refrigerants, such systems have, in the past, been expensive and complicated in design. Such prior systems have generally been suitable only for use in large refrigeration and air conditioning processes and are not suitable for use by the serviceman servicing small air conditioning units such as are used in vehicles or window units, or other cooling systems of the domestic type.
Because of the maintenance requirements of automotive air conditioning systems, connections are typically provided near both the low pressure suction port and the high pressure discharge port of the compressor, which connections can be conveniently utilized to recover and charge refrigerant to the system. Prior refrigerant recovery systems have typically utilized a vacuum pump which would be connected to the low pressure side of the compressor for withdrawing refrigerant from the unit being serviced and compressing the refrigerant and forcing it into a condenser to cool and condense the refrigerant into a liquid. The liquid would then be stored in a storage container. The vacuum pumps in such units are subjected to rigorous pressures and operating conditions and are subject to mechanical difficulties.